1. Field of the Invention
This invention is a device for children""s bicycles which resembles a motorcycle exhaust pipe in appearance and imitates or emulates the sound of a motorcycle engine.
2. Brief Summary of the Prior Art
There are several known devices for emulating the sound of a combustion engine, including U.S. Pat. Nos. 2,620,764; 3,210,889 and 3,439,926. These devices propose constructions with side plates having a plastic finger/contact mount on them. The whole plate is usually mounted on the bicycle frame directly and the plastic contact interferes with the travel of the bicycle wheel spokes to make the repetitive noise vibrations. These devices did not concentrate or direct the noise created by the vibrating contact and allowed said noise vibrations to dissipate into the surrounding air.
More recently, U.S. Pat. No. 4,151,677 by Tucker (May 1, 1979) teaches an adjustable noisemaker with contact arms of varying length, thickness and width. The arms can be selected by the user to determine the kind and volume of noise produced. The body of the noisemaker is a fanciful design, resembling a jet engine housing; the body has no perceptible acoustic function. Contact arms cannot be replaced.
U.S. Pat. No. 4,737,592 by Griffin (Apr. 5, 1988) proposes a conical hollow member attached to the frame of the bicycle, which conical member retains a vibrating arm inserted into the spokes of the bicycle. The conical member concentrates, directs, and amplifies the sound vibrations from the contact arm.
Each of the two most-recently patented devices can be attached to the horizontal bicycle frame in any conventional manner.
This noise-making device (hereafter xe2x80x9cbike pipexe2x80x9d) is shaped like the exhaust tailpipe of a motorcycle. The bike pipe is mounted on the uprising rear wheel support of a child""s bicycle frame. When the bicycle is pedaled the bike pipe emits a loud sound similar to that of a running motorcycle engine.
The bike pipe has four (4) basic parts:
1. A hollow horn-shaped pipe.
2. A rotatable cap.
3. A replaceable flexible spoke contact.
The bike pipe possesses a universal mount that ensures quick, simple, proper mounting of the device on all children""s bicycles, requiring nothing more than a wrench to remove and replace the rear wheel axle nut.
When attached to a bicycle, the pipe extends up and away to the rear wheel at a right angle to the direction of travel of the spokes. When the wheel rotates, the spokes one by one pick up the flexible contact, carry it to the limit of its travel path and drops it, causing a loud roaring vibration to travel down the length of the pipe and up behind the moving bicycle where it can be easily heard by the child riding the bicycle. The vibrations emanating from the pipe are aimed generally upwards making it difficult to detect once the bicycle has traveled a short distance away.
Previous designs of similar bicycle noise-making devices have set the spoke-engaging member halfway down a pipe parallel to the long axis of the pipe. These configurations are inferior to the bike pipe because they broadcast half of the vibrations from the spoke contact down and out of the pipe and the other half up to a closed end where they reflect back toward the spoke engaging member. The reflected vibrations have a tendency to destructively interfere with and cancel new vibrations, especially the more desirable lower frequencies.
The bike pipe design with the flexible spoke contact set inside the cap on the forward end of the pipe perpendicular to the long axis of the pipe allows all the vibration to be broadcast down and out of the pipe and eliminates any destructive interference with low-frequency vibration.
The spoke contact is held in place by the cap snapping onto the pipe. This assembly is efficient and unique. There may also be a adjustable tuning bolt inserted into the cap for changing the pitch of the vibrations of the spoke contact. By tightening or loosening the tuning bolt, the tone of the vibrations can be changed from the low compression tone of a Harley Davidson to the higher smoother pitch of the popular four cylinder Japanese motorcycles. The cap rotates 90 degrees to the left or right depending on which side of the bicycle the device is mounted on, allowing the device to be turned on or off.
The bike pipe design is far superior to the previous art bicycle noisemakers that resemble an exhaust pipe and mimic the sound of an engine. The bike pipe sound is louder to the child riding the bicycle yet barely audible 100 feet away, reducing neighborhood noise pollution. It is much simpler to attach. It can be turned on and off by merely pushing or pulling a lever. Its tone can be adjusted by tightening or loosening a tuning bolt. The spoke contact is cheap and very easily replaced, even by a child.
An object of the present invention is to provide a simulated motorcycle exhaust pipe device attachable to a child""s bicycle that simulates or emulates the sound of a motorcycle engine exhaust. This device will be easily attachable and detachable to/from the bicycle frame.
Another object of this invention is to provide a low-cost spoke-engaging contact member that can be easily replaced, even by a child.
Another object of the invention is to provide an acoustically efficient housing for the device which concentrates the sound made by the device and minimizes internal sonic interference in the housing.
A further object of the invention is to provide a device that will engage the rotating bicycle wheel spokes nearer the hub of the wheel, decreasing stress on the spokes at the rim end or in the middle, preventing the spokes from loosening at the attachments or suffering metal fatigue.
A further object of this invention is to minimize the interference with the pedaling foot of the bicycle rider by permitting placement of the device behind the hub of the rear wheel.
A further object of this invention is to provide a practical mounting device for the invention, suitable for attachment to the frame of any bike with any tube size frame.
A further object of this invention is to make the device such that it can be turned off (disengaged) without dismantling the entire device.